Suomy, you said
"As a result, dancers can't benefit from shoes designed to spread their weight out over a larger area - we have to be able to focus our weight to a very small area, very precisely (this is probably why good dance shoes have very soft soles). Small movements of the focus point of the weight will be felt by the partner, and hopefully responded to."
This discussion about orthotics was an irrelevance all along, but in any case, orthotics aren't designed to spread the weight out over a larger area. An arch support might do this, but that's only one sort of orthotic. Also, as far as the wearer is concerned, he or she feels the shift of weight distribution through the foot as part of dance movement, and there is still a 'focus'. The only difficulty is that some orthotics stiffen the shoe, and this is a disadvantage. The partner responds to body movements and these would be modified by a stiffened shoe.
Can we get back to the original discussion and get some common ground on whether all T-H steps (i originally talked about opening into a promenade figure, but i think moving on from a chassis is similar)require ALL the weight to be on the heel, for any period of time. Yes or no on this?